 /*******************************************************************************
  * Copyright (c) 2000, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal.editors.text;

 import java.util.HashMap ;
 import java.util.Iterator ;
 import java.util.Map ;

 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Display;

 import org.eclipse.jface.text.source.ISharedTextColors;

 /*
  * @see org.eclipse.jface.text.source.ISharedTextColors
  * @since 2.1
  */
 class SharedTextColors implements ISharedTextColors {

     /** The display table. */
     private Map fDisplayTable;

     /** Creates an returns a shared color manager. */
     public SharedTextColors() {
         super();
     }

     /*
      * @see ISharedTextColors#getColor(RGB)
      */
     public Color getColor(RGB rgb) {
         if (rgb == null)
             return null;

         if (fDisplayTable == null)
             fDisplayTable= new HashMap (2);

         final Display display= Display.getCurrent();

         Map colorTable= (Map ) fDisplayTable.get(display);
         if (colorTable == null) {
             colorTable= new HashMap (10);
             fDisplayTable.put(display, colorTable);
             display.disposeExec(new Runnable () {
                 public void run() {
                     dispose(display);
                 }
             });
         }

         Color color= (Color) colorTable.get(rgb);
         if (color == null) {
             color= new Color(display, rgb);
             colorTable.put(rgb, color);
         }

         return color;
     }

     /*
      * @see ISharedTextColors#dispose()
      */
     public void dispose() {
         if (fDisplayTable == null)
             return;
         
         Iterator iter= fDisplayTable.values().iterator();
         while (iter.hasNext())
             dispose((Map )iter.next());
         fDisplayTable= null;
     }
     
     /**
      * Disposes the colors for the given display.
      *
      * @param display the display for which to dispose the colors
      * @since 3.3
      */
     private void dispose(Display display) {
         if (fDisplayTable != null)
             dispose((Map )fDisplayTable.remove(display));
     }
     
     /**
      * Disposes the given color table.
      *
      * @param colorTable the color table that maps <code>RGB</code> to <code>Color</code>
      * @since 3.3
      */
     private void dispose(Map colorTable) {
         if (colorTable == null)
             return;
         
         Iterator iter= colorTable.values().iterator();
         while (iter.hasNext())
             ((Color) iter.next()).dispose();
         
         colorTable.clear();
     }

 }

